Quality INSIGHTS

Segmented filamentous bacteria (SFB, provisional classification Candidatus Savagella) are commensal microorganisms endemic to all vertebrate classes, including mice and humans. SFB are notable for their ability to modulate adaptive host immune responses, including induction of regulatory Th17 T cells, Peyer's patch maturation, and gut IgA production1-3. A recent study from the laboratory of Joyce Wu at the University of Arizona has revealed a novel innate immune function...  Read More

In May 2018 researchers at the University of California-Davis and Université de Strasbourg published a paper titled, A Population Study of Common Ocular Abnormalities in C57BL/6N rd8 Mice in the journal, Investigative Ophthalmology and Visual Science. C57BL/6N mice, which carry the rd8 mutation, are the most commonly used model for generation of knockout models. This study looked at a large cohort of C57BL/6N mice which were sourced...  Read More

With growing alarm at the failure to replicate published, influential studies, the life sciences community is turning their attention to the causes and consequences of the replication crisis. How can we improve in vivo research to secure the reliability of our results? Reproducibility in Life Sciences While some of the most public replication failures came out of the "softer" sciences, such as psychology or economics, the biological...  Read More

Proposed changes to the ICH S1 guidelines for rodent carcinogenicity testing of human pharmaceuticals would allow sponsors to waive the requirement for a two-year rat bioassay under certain conditions. A final ruling and guidance update are expected in June of 2018. Re-Examining Carcinogenicity Testing In 2011, Sistare et al. conducted a retrospective analysis of the data on two-year rat carcinogenicity and chronic toxicity studies in rats with...  Read More

Timed pregnant mice and rats are important research tools, with applications in developmental research, genetic engineering, and generating tissue cultures. They are the most efficient way to obtain a cohort of embryos, fetuses, or pups with a precisely defined, matched age. But what exactly are timed pregnant mice? What Are Timed Pregnant Mice and Rats? A timed pregnant female is a mouse or rat with a precisely...  Read More

A frankly shocking amount of research funding — perhaps as high as 85%, or $200 billion — is wasted on poorly designed studies. How can you improve your study design to avoid falling into this trend? Each day scientists plan, conduct, analyze and debate study design, hoping their efforts will lead to a cure or a new understanding of a critical biological pathway. Is it easy? No...  Read More

What is genetic quality and how does it impact in vivo research? Dr. Ana Perez addressed this topic in a recent webinar, making the case that research reproducibility requires high genetic quality of laboratory rodents. Genetic Background Categories In terms of their genetic background, Dr. Perez divided animal models into four basic categories. Each category requires a distinct approach to maintaining genetic integrity: Inbred strains have a...  Read More

Proper sample size calculation is both a scientific and ethical imperative. Researchers are routinely asked to justify the number of animals used in their studies, either by regulatory bodies, funding agencies or, increasingly, by journal editors. In accordance with the 3R's, studies should be designed to reduce the number of animals used to meet scientific objectives. While the ethical reasons underlying such reductions are obvious, it is...  Read More

Quality and reproducibility are the focus of much scientific literature, reviews, and commentaries. Knowledge cannot advance without confidence in the reproducibility of our research. If you work in a laboratory animal facility or use animal models in your research, you know proper training is imperative to quality, reproducibility, and success. Yet, there is no single source of information, regulations, or training materials we can turn to. The...  Read More

In the spirit of Russell and Burch's 3Rs, scientists are developing new tools and methodologies to reduce the use of animal models wherever possible. A very good example is the rasH2 mouse model, which was developed as an alternative to the traditional, two-year carcinogenicity testing of compounds for mutagenic and non-mutagenic chemically- induced tumor formation. Transgenic Mice as an Ethical Alternative The rasH2 mouse was developed in...  Read More